For the orzo and broccoli rabe: Bring a large pot three-fourths full of salted water to a boil. Add the broccoli rabe and cook until almost tender-crisp, about 2 minutes. Using a slotted spoon, transfer the broccoli rabe to a medium bowl. Add the orzo to the water and cook until almost tender but still firm to the bite, about10 minutes. Return the broccoli rabe to the pot to heat through, and then drain the orzo and broccoli rabe well. Return the orzo and broccoli rabe to the hot pot and mix in the oil, thyme, and lemon zest. Season to taste with salt and pepper. Cover to keep warm.
Meanwhile, prepare the shrimp: Warm the oil in a large nonstick skillet over medium heat. Add the shallot and sauté until beginning to soften, about 1 minute. Add the tomato paste and red pepper and sauté 30 seconds. Add the wine and lemon juice and bring to a boil. Add the shrimp, sprinkle with salt and pepper and sauté until just cooked through, stirring frequently, about 3 minutes. Taste and adjust the seasonings.
Place the orzo mixture in a warmed bowl. Top with the shrimp and serve right away.